Motor vehicle window assemblies having one or more sliding panes, that is, panes which slide either substantially horizontally or vertically with respect to the window assembly, may be either manually operated or operated by an electric motor. Such window assemblies are used, for example, as rear slider windows for pickup truck cabs, typically having a circumferential (that is, outer peripheral) frame in which are mounted a sliding pane along with one or more fixed panes. The frame may be structural or semi-structural in that it integrates the sliding pane and one or more fixed panes as a self-contained preassembled module suitable for shipping and handling during installation into a motor vehicle.
Power sliding window assemblies are increasingly popular, particularly when used for backlights in pickup trucks, as it is awkward for the driver of a pickup truck to reach behind his seat and open a manually operated sliding window assembly. A power window assembly for a vehicle having a sliding pane is shown in U.S. Pat. No. 5,724,769 to Cripe et al. Cripe et al is a robust design for a pull-pull power sliding window assembly having left and right fixed panes and a horizontally sliding center pane sliding between upper and lower run channels. A drive motor, drive drum and drive cable pull the sliding pane back and forth in a manner similar to conventional cable drum window regulators. Cable directional blocks route drive cable from below the frame to a lower horizontal peripheral edge of the sliding pane. The drive cable is routed through a serpentine passageway in the cable directional blocks so as to extend generally parallel with the direction of travel of the sliding pane. Such a design advantageously routes the cables so as to avoid excessive drag associated with pulling the sliding pane up against the upper run channel or down against the lower run channel.
While such a design is excellent for reducing friction and thereby minimizing wear and tear, such designs can be difficult to assemble. This is particularly the case where retrofitting kits are used. Such kits are used to retrofit a sliding window assembly from manual to power. The difficulty in assembly using a retrofit kit occurs because there is insufficient "slack" in the cable to easily attach the cables to the sliding pane (or bracketry which is in turn connected to the sliding pane). The term slack is used here and by others skilled in the art to refer to the length of cable that extends beyond a semi-rigid conduit that the cable travels in for guidance. Such slackness is highly advantageous for ease of assembly, particularly connecting the cable to the sliding pane. Of course, the cables used in such applications stretch insignificantly. Instead, the springs urge the conduit to move with respect to the cable, and the more cable that extends from the conduit, the more "slack" the cable is. In a retrofit kit, the cables will have been previously wrapped around the drive drum and the springs have expanded move to the position where the cables extend little beyond the conduit. In this condition, the cables are not slack. In comparison, conventional cable drum mechanisms are connected to the sliding pane (or bracketry to be connected to the sliding pane) before the cable is wrapped around the drive drum. Thus, other means must be provided to allow for slack in the cable of retrofit kits for sliding window assemblies.
It would be desirable to provide a power sliding window assembly that is easy to assemble, particularly when used as a retrofitting kit.
In view of the foregoing, it is an object of the present invention to provide an easy to assemble pull-pull power sliding window assembly. It is an additional object of certain embodiments of the present invention to provide a retrofitting kit for retrofitting a manual sliding window assembly installed in a motor vehicle. It is another related object of the present invention to provide a pull-pull power sliding window assembly that is highly reliable in operation. Additional objects and optional features of the invention will be apparent form the following disclosure and detailed discussion of preferred embodiments.